I. Field
The present disclosure relates generally to communication, and more specifically to techniques for encoding and decoding data.
II. Background
In a communication system, a transmitter may encode a packet of data to obtain code bits, interleave the code bits, and map the interleaved bits to modulation symbols. The transmitter may then process and transmit the modulation symbols via a communication channel. The communication channel may distort the data transmission with a particular channel response and further degrade the data transmission with noise and interference. A receiver may obtain received symbols, which may be distorted and degraded versions of the transmitted modulation symbols. The receiver may process the received symbols to recover the transmitted packet.
The encoding by the transmitter may allow the receiver to reliably recover the transmitted packet with the degraded received symbols. The transmitter may perform encoding based on a forward error correction (FEC) code that generates redundancy in the code bits. The receiver may utilize the redundancy to improve the likelihood of recovering the transmitted packet.
Various types of FEC code may be used for encoding. Some common types of FEC code include convolutional code, Turbo code, and low density parity check (LDPC) code. A convolutional code or a Turbo code can encode a packet of k information bits and generate a coded packet of approximately r times k code bits, where 1/r is the code rate of the convolutional or Turbo code. A convolutional code can readily encode a packet of any size by passing each information bit through an encoder that can operate on one information bit at a time. A Turbo code can also support different packet sizes by employing two constituent encoders that can operate on one information bit at a time and a code interleaver that can support different packet sizes. An LDPC code may have better performance than convolutional and Turbo codes under certain operating conditions. However, an LDPC code is typically designed for a particular packet size and may not be able to readily accommodate packets of varying sizes.
There is therefore a need in the art for techniques to support efficient LDPC encoding and decoding of packets of varying sizes.